Detachable surgical ratchet

ABSTRACT

A surgical ratchet assembly includes a handle, a driver, a ratcheting mechanism and a locking mechanism. The driver is received within the handle in a rotatable relationship with respect thereto. The ratcheting mechanism is interposed between the handle and the driver. A locking mechanism releasably holds the handle to the ratchet mechanism. Unlocking of the locking mechanism enables ready disassembly of the assembly for cleaning and component sterilization.

BACKGROUND OF THE INVENTION

This invention relates to drivers for rotary surgical cutting tools,and, more particularly, to drivers used in maxillo-facial, neuro,dental, trauma and orthopedic surgery, including reamer drivers.

Surgical ratchets are complicated mechanical devices which have crevicesand recesses that, heretofore, have been difficult, if not almostimpossible to clean with ease. Devices that are not properly cleaned andsterilized run the risk of disease transfer from patient to patientfollowing the emergence of certain “prions” that are not killed bynormal hospital sterilisation and need to be physically removed bywashing/rinsing. For this reason, in the prior art, ratchet mechanismshave be hermetically sealed to prevent contamination. However, the sealsare not 100% reliable.

What is needed therefore is a surgical ratchet that is easilydisassemblable for cleaning, so as to better ensure sterilization.

SUMMARY OF THE INVENTION

A surgical ratchet assembly includes a handle, a driver, a ratchetingmechanism and a locking mechanism. The driver is received within thehandle in a rotatable relationship with respect thereto. The ratchetingmechanism is interposed between the handle and the driver. Theratcheting mechanism includes pawls which can be selectively locked outof engagement with a toothed hub via a selector. A locking mechanismreleasably holds the handle to the ratchet mechanism. Unlocking of thelocking mechanism enables ready disassembly of the assembly for cleaningand component sterilization.

Although the term “driver” is used herein, this terms is meant toencompass drills, taps, guide pins, screwdrivers (for example, straight,cross-head, Allen key and Torx), reamer drivers, and wire introducersand any tool to which rotation and torque need be applied.

In another feature, the selector includes a position in which both pawlsare in an engaged position, thus locking the ratchet mechanism againstfree movement in either direction.

In another feature, the selector includes a position in which both pawlsare in a released, nonengaged position, disengaging the ratchetmechanism, thus permitting free motion in either direction.

An object of the invention is to provide a surgical ratchet that isreadily disassembled for cleaning and sterilization.

Another object of the invention is to provide a reliable ratchet that iseasy to operate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the ratchet of the invention.

FIG. 2A is cross sectional view of the ratchet of the invention.

FIG. 2B is a cross sectional detail of the upper right corner of theratchet of FIG. 2A.

FIG. 3 is a partially disassembled view of the ratchet of the invention.

FIG. 4 is a perspective, partically disassembled view of the ratchet ofthe invention.

FIG. 5 is a perspective, cross sectional view taken along plane A ofFIG. 1, showing the components of the ratchet mechanism of theinvention.

FIG. 6 is a perspective view of a kit of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In a preferred embodiment, as shown in FIGS. 1 to 3, a surgical ratchetassembly 10 includes a handle 12, a driver 14, a ratcheting mechanism 16and a locking mechanism 20. The driver 14 is received within the handle12 in a rotatable relationship with respect thereto. The ratchetingmechanism 16 is interposed between the handle 12 and the driver 14. Thelocking mechanism 20 releasably holds the handle 12 to the ratchetmechanism 16. Unlocking of the locking mechanism 20 enables readydisassembly of the assembly 10 for cleaning and component sterilization.

The locking mechanism 20 includes a ring 24 which is mounted over anannular surface on a hub 28 non-rotatably affixed to the handle 12. Thering 24 has an external surface which is preferrably polygonal in crosssection in order to provide a grip to facilitate operation by the user.The ring 24 is locked by a retainer ring, set screw or other fastener(not shown) so as to be restrained to axially rotate about the handle12. The inner surface of the ring 24 includes equally spaced apart balls32 restrained in recesses 33 of the hub 28. The balls 32 are selectivelybiased into or out of an annular recess 34 in the annular rearward end36 of the driver 14.

The driver 14 includes the end 36 affixed to a central shaft 38 on whichis formed a toothed hub 52. The end 36 is formed of a material that canwithstand impaction of a mallet and effectively transmit the forces soinput through the driver 14 to the object being impacted.

Referring now to FIGS. 4-5, the ratcheting mechanism 16 is made up of aninternal housing 22, left and right hand pawls 44, 46, a selector 50,the toothed hub 52, biasing springs 40, and cam portions 53.

The selector 50 rotates about the axis 54 of the driver 14, about an end56 of the handle 12, and selectively locks, via a spring detent 60 (bestshown in FIG. 2B) in one of two recesses 62 in the internal housing 22,at two extreme positions. The spring detent 60 is made up of a plunger60, spring 51, enclosed by a plug 55. The selector 50 has an internalsurface 64 having cam portions 53 (referring in particular to FIG. 4,adjacent the right ends 66, 67 of the pawls 44, 46, respectively) whichselectively engage the end of either the left or right hand pawls. Intoothed hub 52, and therefore the driver 14, is keyed against rotationrelative to the handle 12 and therefore moves with the handle. In otherwords, when the handle 12 is rotated, the toothed hub 52 and driver 14rotates.

It should be noted that the handle 12 is generally formed of a polymericmaterial that is comfortable to grip, but which includes inserts 18 toadd structural rigidity.

Referring again to FIG. 2A, the pawls 44, 46 are formed so as to engagewith the symmetrical, circumferential teeth 80 of the toothed hub 52,thus preventing motion in one direction, while permitting rotation inthe opposite rotation. In the present embodiment, the pawls 44, 46 havefingers presenting a flat, locking surface 44′, 46′ which, when the camplaces them in an operational position, engages and therefore blocks atooth 80 of the toothed hub 52 when the hub is urged in one rotationaldirection with respect to the handle 12, and an opposing angled surface44″, 46″, which does not lockingly engage a tooth of the toothed hub,but enables relative rotation of the pawl and toothed hub, when urged inthe opposite direction. The pawls 44, 46 are supported against bendingin channels 82 of the housing 22.

The pawls 44, 46 are pivotally mounted in the housing 22 on pins 84 andnormally urged into an engaging relationship by springs 40, the camportions 53 of the selector 50 selectively moves one or the other out ofengagement with the toothed hub 52, thus enabling a user to drive thedriver 14 in one direction by turning the handle 12, while permittingrelative movement of the toothed hub and the pawls when the handle isturned in the other direction. Thus, movement of the selector 50 in oneor the other extreme positions allows the user to select a ratchetingdirection.

In a mid position, in which there may optionally be a spring detent, theinternal surface 64 is at a low point 64′, and thus the cam portions 53of the selector 50 place both pawls 44, 46 in an operational position soas to block rotation in both directions, enabling a functioning just asa normal, non-ratcheting driver.

In another mid position, the cam of the selector 50 optionally movesboth pawls 44, 46 out of engagement with the toothed hub 52, thusproviding a neutral position in which the handle 12 is free to turn ineither direction.

The driver 14 includes a fitting interface 90 on an end of the centralshaft 38. The shaft 38 extends from the front to the rearward end of theratchet 10. The fitting interface 90 interfaces with an AO fitting, aSnyder fitting, or another known fitting 58. A fitting locking mechanism94 locks the fitting (not shown) into engagement with the driver 14. Thefitting locking mechanism 94 includes a locking sleeve 100, axiallybiased by a spring 96 acting against a recess 94 in the selector 50.

The ratchet 10 enables easy dissassembly for cleaning, which involvesthe following steps. In a first disassembly step, the locking ring 24 istwisted to an unlocked position. In a second disassembly step, theinternal ratchet body 108 (the assembled-together driver 14 and ratchetmechanism 16) is removed for cleaning.

Further, a simple method of assembly is provided which includes thefollowing steps. In a first assembly step, the ratchet body 108 isinserted into the handle 12. In a second assembly step, an alignment pin(not shown) is aligned with a slot 102 in the handle 12 in order thatthe user properly aligns the ratchet body with the handle. In a thirdassembly step, the body 108 is pushed into the handle 12 until it can gono further. In a fourth assembly step, the locking ring 24 is thentwisted into a locking position. In an optional fifth assembly step, atool 58 is selected from a kit 150, and inserted into the driver 14. Theratchet assembly 10 is now ready for use.

Referring now to FIG. 6, the kit 150 is shown, including the ratchet 10,a a tool 130, 132, 134, 136, a T-bar 138 and a guide pin 139. Thecomponents of the kit 150 are organized in a case 160 for convenience.

The T-bar 138 includes a square plug drive that mates with the end 36having a corresponding female socket 140. In this alternate embodiment,the end 36 is either integral with or firmly affixed to the othercomponents of the driver 14 so as to be able to effectively transmittorque therethrough.

In an advantage of the invention, a surgical ratchet is provided that isreadily disassembled for cleaning and sterilization.

In another advantage of the invention, a reliable ratchet is providedthat is easy to operate.

In another advantage, an assembly method is provided involving only afew simple steps.

In another advantage, a kit is provided which presents the ratchet 10and related components to the surgeon in a convient, organized fashion.

In another advantage, a T-bar attachment enables increased torque to betransmitted through to the object being driven, by virtue of the largelever arm distance afforded by the T-bar. Convenience is gained becauseit is not necessary to re-grip the T-bar each time torque is to beinput—rather, the ratchet mechanism enables easy and advantageousrepositioning.

Multiple variations and modifications are possible in the embodiments ofthe invention described here. Although certain illustrative embodimentsof the invention have been shown and described here, a wide range ofmodifications, changes, and substitutions is contemplated in theforegoing disclosure. In some instances, some features of the presentinvention may be employed without a corresponding use of the otherfeatures. Accordingly, it is appropriate that the foregoing descriptionbe construed broadly and understood as being given by way ofillustration and example only, the spirit and scope of the inventionbeing limited only by the appended claims.

1. A surgical ratchet (10) having a handle (10), a driver (14) receivedwithin the handle in a rotatable relationship with respect thereto, aratcheting mechanism (16) interposed between the handle and driver, anda locking mechanism (20) releasably holding the handle to the ratchetmechanism, wherein displacing of the locking mechanism to an unlockposition moves a locking obstruction (32) out of an obstructing positionthereby permitting easy release of the ratchet mechanism from the handleand ready disassembly of the ratchet mechanism from the handle.
 2. Theratchet (10) of claim 1, wherein the locking mechanism (20) comprises aring (24) rotatable on the handle (12), the ring having a surfaceselectively biasing a ball (32) into or out of a recess (34) to engageor disengage the ratchet mechanism (16) to lock or unlock the assembly.3. The ratchet (10) of claim 1, wherein the locking mechanism (20)comprises a surface against which a user may apply pressure toeffectuate a change in interactivity of components in order to engage ordisengage the ratchet mechanism (16) to lock or unlock the assembly. 4.The ratchet (10) of claim 1, wherein a selector (50) enables a user toactivate, disactivate, or lock the ratcheting mechanism (16).
 5. Theratchet (10) of claim 1, wherein the locking mechanism (20) is comprisedof a selector (50) having a position in which at least one pawl (44, 46)is in an engaged position, wherein, when the selector is in the engagedposition, the at least one pawl locks the ratchet mechanism against freemovement in a selected direction.
 6. The ratchet (10) of claim 1,wherein the locking mechanism (16) is comprised of a selector (50)having a position in which at least one pawl (44, 46) is in a releasedposition, wherein, when the selector is in the released position, the atleast one pawl disengages the ratchet mechanism, thus permitting freemotion in either direction.
 7. The ratchet (10) of claim 1, wherein aportion of the driver (14) protrudes from an end (36) of the handle(12), thereby presenting an impaction surface enabling the ratchet to beused as an impactor.
 8. The ratchet (10) of claim 1, wherein theratcheting mechanism (16) comprises (a) a housing (22) in which left andright hand pawls (44, 46) are pivotably connected and selectivelypivotably engageable by a cam selection device (50) for selection of aratcheting direction; and (b) a toothed hub (52) connected, at leastindirectly, to the handle.
 9. The ratchet (10) of claim 8, wherein thecam selection device (50) comprises a cam having a cam surface (53)against which an end (66, 67) of the at least one pawl (44, 46) ridesand wherein relative movement of the cam surface to the end of the atleast one pawl causes the pawl to pivot in a prescribed manner.
 10. Theratchet (10) of claim 8, wherein an end (66, 67) of the at least onepawl (44, 46) engaging the toothed hub (52) is formed so as to permitrelative rotation with respect to the hub in one rotational direction,and to block rotation in the opposite rotational direction.
 11. Asurgical ratchet (10) having a handle (12), a driver (14) receivedwithin the handle in a rotatable relationship with respect thereto, aratcheting mechanism (16) interposed between the handle and driver, anda locking mechanism (20) releasably holding the handle to the ratchetmechanism, wherein the locking mechanism (20) comprises a ring (24)rotatable on the handle, the ring having a surface (53) whichselectively biases a ball (32) into or out of a recess (34) to engage ordisengage the ratchet mechanism (16) to lock or unlock the assembly,whereby displacing of the locking mechanism (20) into an unlock positionmoves a locking obstruction (32) out of an obstructing position therebypermitting easy release of the ratchet mechanism from the handle andready disassembly of the ratchet mechanism from the handle, wherein theratcheting mechanism (16) comprises (a) a housing (22) in which left andright hand pawls (44, 46) are pivotably connected and selectivelypivotably engageable by a cam selection device (50) for selection of aratcheting direction, the cam selection device comprising a cam having acam surface against which an end of the at least one pawl rides andwherein relative movement of the cam surface to the end of the at leastone pawl causes the pawl to pivot in a prescribed manner, (b) a toothedhub (52) connected, at least indirectly, to the handle, and (c) aselector (50) which has a position in which at least one pawl (44, 46)is in an engaged position, wherein, when the selector is in the engagedposition, the at least one pawl locks the ratchet mechanism against freemovement in a selected direction, thus enabling a user to activate,disactivate, or lock the ratcheting mechanism.
 12. The ratchet (10) ofclaim 1, wherein the handle (12) is a T-bar (138).
 13. The ratchet (10)of claim 1, wherein the handle (12) includes an interface (140) forreceiving a T-bar attachment (138).
 14. A tool kit (150) for surgicaluse, the tool kit including at least the following components: (a) asurgical ratchet (10) having a handle (12), a driver (14) receivedwithin the handle in a rotatable relationship with respect thereto, aratcheting mechanism (16) interposed between the handle and driver, anda locking mechanism (20) releasably holding the handle to the ratchetmechanism, wherein displacing of the locking mechanism to an unlockposition moves a locking obstruction (32) out of an obstructingposition, thereby permitting easy release of the ratchet mechanism fromthe handle and ready disassembly of the ratchet mechanism from thehandle, (b) at least one tool selected from a group of tools consistingof drills (134), taps (136), guide pins (130), screwdrivers (132),reamer drivers, and wire introducers; and (c) a case (160) for receivingthe ratchet and the at least one tool.